1. Field of the Invention
This invention generally relates to semiconductor fabrication and, more particularly, to a solid-state inductor for analog integrated circuit (IC) fabrication and a method for processing the same.
2. Description of the Related Art
Conventionally, an IC integrated inductor is formed from a metal line, designed in spiral form, overlying a thick layer of insulator on silicon substrate. The inductance value of an inductor so formed is very low, so that the formation of a practical inductor requires a large silicon area. Besides using a great amount of valuable IC area, the large-sized inductors generate parasitic reactances and unintended mutual inductances with components that are adjacent, overlying, or underlying the inductor.
Further, a conventional inductor is a passive component, meaning that once it is formed in the IC, the inductance value cannot be changed. Thus, the inductor cannot be used for frequency tuning. Frequency tuning would be desirable in the fabrication of circuits such as filters, antennas, and oscillators, to name a few of examples.
It would be advantageous if an IC inductor could be made smaller, with a greater inductance value.
It would be advantageous if the inductance value of an IC inductor could be varied or tuned in an IC circuit.